The Seattle Mariners are a Major League Baseball team based in Seattle, Washington. They are in the Western Division of the American League.
- Founded: 1977 (American League expansion)
- Home ballpark: Safeco Field (1999-present), Kingdome (1977-1999).
- Uniform colors: Navy Blue, Emerald Green, Silver
- Logo design: A baseball on an 8-pointed compass.
- Wild Card titles won (1): 2000
- Division titles won (3): 2001, 1997, 1995
- League pennants won (0): none
- World Series championships won (0): none
The Mariners were added to the American League in 1977, and were for many years perennial non-achievers. Despite having stars such as Alvin Davis and Gaylord Perry, the Mariners did not have a winning record until 1991.
By the mid 1990s, under manager Lou Piniella, the Mariners added a core of strong players built around center-fielder Ken Griffey, Jr, pitcher Randy Johnson and designated hitter Edgar Martinez. They won their first division title in 1995, having trailed the California Angels by 13 games in mid-August. Their dramatic championship run that year was halted in the ALCS by the Cleveland Indians. The Mariners won the division title again in 1997.
In 2001, despite the loss of superstar shortstop Alex Rodriguez, the addition of Japanese sensation Ichiro Suzuki helped the Mariners to have one of the most successful regular seasons on record, leading the major leagues in winning percentage from start to finish, easily winning the American League West championship, setting a new American League record for most wins in a single season (116), and matching the major league record for single season wins set by the Chicago Cubs in 1906. They pulled off a come-from-behind 3-2 series win over the Cleveland Indians in the ALDS to advance to the American League Championship Series against the New York Yankees, but succumbed to the Yankees for the second year in a row in the ALCS, 4 games to 1.
At the end of the 2002 season, manager Lou Pinella left the Mariners to manage the Tampa Bay Devil Rays. The Mariners signed Bob Melvin to be their new manager. Despite an excellent start to the 2003 season, the Mariners failed to make the playoffs in 2003.